Bearing



May 2, 1961 G. D. FRASER ET AL 2,982,587

BEARING Filed April 22, 1958 INVENTORS GROVER 0. FRASER- JOHN LE VALLEY THEIR ATTORNEY BEARING Grover D. Fraser and John Le Valley, Painted Post, N.Y., assignors to Ingersoll-Rand Company, New York, N.Y., a corporation of New Jersey FiledApr. 22, 19-58, Ser. No. 730,103 r 3 Claims. (Cl. 308-174) .the rotor he accurately locatedin its pump casingto avoid frictional contact between the rotor and the pump casing. In conventional rotary vane pump construction each end of the pump shaft is provided with a thrust bearing additionally serving as radial bearings. The disadvantages of this construction are that both bearings may have to be shimmed when initially positioning the rotor to achieve the desired location thereof in the pump casing, or, when disassembly of the pump is required both bearings may have to be reshimmed when reassembling the pump. The present invention eliminates these disadvantages by providing a' single thrust bearing device operating on only one side of the rotor.

The principal object of the present invention is 10 provide a device which will facilitate reassembly of the pump, after being disassembled, by eliminating reshimming.

A further object of the present invention is to provide a device for facilitatingthe initial positioning of the rotor within its casing.

Another object of the present invention is to provide a device to maintain the initial position of the rotor in its casing during operation.

Still another object of the present invention is to provide a device which is reliable, simple and eflicient.

Another object of the present invention is to simplify the construction of vane type pumps.

These and other objects and advantages of this invention will more fully appear from the following description made in connection with the accompanying drawings, in which- Figure 1 is a cross section of a vane type pump showing the arrangement of the present invention, and

Fig. 2 is a section taken on the line 2--2 of Figure 1 and looking in the directionbf the arrows.

Referring now, more particularly, to the drawings the pump assembly A as shown in Figure 1 includes a casing 10 having a cylindrical bore '12. A rotor 14, provided with vanes 16, is slidably mounted within the bore 12 and enclosed therein by removable heads 20 and 22 connected to the casing 10. The rotor 14 is mounted on a shaft 18 which rotates in bearings 24 and 26 mounted in the heads 20 and '22, respectively. The bearings 24 and 26, conventional radial type roller bearings, serve to support the radial load of the shaft 18 and are mounted in a well known manner and positioned as illustrated in Figure 1. As for the support of the axial load of the shaft 18 a thrust bearing 32 of the common type is provided and mounted preferably on the drive end portion of the shaft 18 in spaced relation with the bearing 26.

According to the invention, only one thrust bearing is used to serve as a means to support the axial load of the shaft 18 as well as to provide for axial adjustment of the shaft 18 and, consequently, the rotor 14 relative I Uni-F St s a n Patented May 2, 19,61

to its casing 10. This is achieved by the arrangement of the thrust bearing 32 in a bearing casing 38 and the cooperation between the bearing casing 38 and the head 22. The thrust bearing 32 is housed in the bearing casing 38 which is connected to be supported to the head 22. The inner race 34 of the thrust bearing 32 is mounted on the shaft 18 spaced from the bearing 26 and positioned between two snap rings 40 and 42 which prevent axial movement of the inner race 34 relative to the shaft 18. The bearing casing 38 has a cylindrical bore 44 of a diameter slightly larger than the outer diameter of the thrust bearing 32 to obtain a clearance between the outer race 36 of the thrust bearing 32 and the cylindrical bore of the bearing casing 38 to prevent the thrust bearing 32 from assuming the radial load of the shaft 18.

The bearing casing 38 is provided with side members 46 and 48 between which the outer race 36 of the thrust bearing 32 is positi0ned, the distance between the opposing faces of the side members 46 and 48 being slightly larger than the width of the outer race 36. As the outer race 36 of the thrust bearing 32 has a loose fit between the side members 46 and 48 the outerjrace 36 is held against rotation by a resilient member, preferably a rubber O-ring 50, partly recessed in the side member 46 and positioned to be compressed between the outer race 36 and the side member 46. It is to be noted that with this arrangement, the O-ring 50 serves a dual purpose: first, it acts as a spring to axially position the thrust bearing 32 and hence the shaft 18 and the rotor 14, and secondly, it acts as a friction brake to resist rotation of the outer race 36 causing wear on the sides of the outer race 36 and side members 46 and 48.

As the bearing casing 38, by reason of its structure, engages the outer race 36 of the thrust bearing 32 and hence controls the position of the inner race 34, shaft 18 and the rotor 14, the position of the bearing casing 38 determines the position of the rotor 14 in its casing 10. In order to regulate the position of the bearing casing 38 an adjustable connection of the bearing casing 38 to the head 22 is arranged. The adjustable connection comprises bolts 52 to support the bearing casing 38, and shims 54 to space the bearing casing 38 from the head 22 in order to regulate the position of the bearing casing 38 axially in either direction. Obviously, the adjustable connection may also be accomplished by using only bolts adapted to space the bearing casing 38 relative to the head 22 in accordance with the proper clearances of the rotor 14 in its casing 10.

It is to be observed that with the thrust bearing 32 arranged only on one side of the shaft 18, removal of the head 20 at the opposite side for repair or inspection of the rotor 14 does not require any disturbance of the thrust bearing 32. It is also to be observed that with only one thrust bearing the initial positioning of the rotor 14 in its casing 10 will require shimming of only the bearing casing 38.

It is to be understood that the invention, shown and described in connection with the preferred embodiment, is not to be restricted to the details set forth since these may be modified within the scope of the appended claims without departing from the spirit and scope of the invention. y

We claim:

l. The combination with a rotary pump comprising, a pump casing having a cylindrical portion closed at its ends by removable heads, a bore in each of said heads in axial alignment with each other, and a rotor in said cylindrical portion mounted on a shaft extending into the bore of each of said heads, of a bearing mounted in each of said bores adapted to rotatably support said shaft, a thrust bearing on one side only of the rotor comprising an inner and an outer race having its inner race mounted on said shaft, and a pair of axially spaced abutments on the shaft to engage therebetween the inner race of the thrust bearing to prevent axial movement thereof relative to the shaft, a bearing casing separate from the pump casing for housing said thrust bearing comprising a cylindrical portion having a diameter slightly larger than that of the outer race of said thrust bearing, and a side member at each end of the second said cylindrical portion spaced axially to engage therebe tween the outer race to positively prevent axial movement thereof relative to the last said cylindrical portion, said bearing casing connected to and supported by the outer end of one of said heads by adjusting means adapted to adjust said bearingcasing axially and hence said shaft and said rotor axially in either direction relative to the pump casing.

2. The combination with a rotary pump comprising, a pump casing having a cylindrical portion closed at its ends by removable heads, a bore in each of said heads in axial alignment with each other, and a "rotor in said cylindrical portion mounted on a shaft extending into the bore of each of said heads, of a bearing mounted in each of said bores adapted to rotatably support said shaft, a thrust bearing on one side only of the rotor comprising an inner and an outer race having its inner race mounted on said shaft in axially spaced relation with respect to one of said bearings, and a pair of axially spaced abutments on the shaft to abuttingly engage therebetween the inner race of the thrust bearing to prevent axial movement thereof relative to the shaft, a bearing casing. for

housing said thrust bearing comprising a cylindrical portion having a diameter slightly larger than that of the outer race of said thrust bearing, and a side member at each end of the second said cylindrical portion spaced axially to positively prevent axial movement of said outer race relative to the last said cylindrical portion, and means in said bearing casing to holdsaid outer race against rotation, said bearing casing removably connected to and supported by the outer end of one of said heads by adjusting means adapted to adjustsaid bearing casing axially and hence said shaft and said rotor axially in either direction relative to the pump casing.

3. The combination claimed in claim 2 in which the means in said bearing casing includes a resilient member on the interior of said bearing casing positioned such to frictionally engage said outer race of said thrust bearing to hold it against rotation.

References Cited in the file of this patent UNITED STATES PATENTS 

